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K Sturm

Publications and source records attributed to K Sturm.

6 recordsLinked to original sources
PubMed1983

5-sulfamoylorthanilic acids, a sulfonamide series with salidiuretic activity.

A series of 4,N-disubstituted 5-sulfamoylorthanilic acids was synthesized by nucleophilic substitution reactions starting either from 2,4-dihalogeno-5-sulfamoylbenzenesulfonic acids or, in most cases, from phenyl 2,4-dihalogeno-5-sulfamoylbenzenesulfonates. The latter method is based on the relative stability of the phenoxysulfonyl group to nucleophiles, e.g., amines, phenols, and thiols, and the possibility of smooth hydrolytic or hydrogenolytic cleavage as a final step, with formation of the SO3H group. On evaluation of these compounds for salidiuretic activity in rats orally (po), and in dogs orally and intravenously (iv), a number of highly active substances was found; the best had a threshold dose of 0.02 mg/kg po in dogs. The results are given in tables, and the structure-activity relationships within the series are discussed. Besides the known effect of the phenoxy radical, an outstanding activating effect was shown by the butylsulfonyl and cycloalkylsulfonyl radicals and by the N-methylanilino radical in particular when they were located in the 4-position of the orthanilic acid molecule. The sulfanilic acid isomers corresponding to three of the most active compounds were synthesized and proved to be completely inactive in rats.

Animals↗
PubMed1982

The contribution of the parallel and series elastic components to the dynamic properties of the rat tail artery under two different smooth muscle tones.

The dynamic elastic modulus (Ed) and the coefficient of wall viscosity (eta w) of the tail artery of normotensive rats were determined as functions of the circumferential wall stress under quasistatic and dynamic conditions. The experiments were performed under strong smooth muscle activation induced by norepinephrine, and during relaxation induced by papaverine. The following results were obtained. 1. Ed and eta w increase with increasing wall stress. At a given wall stress, Ed is virtually independent of frequency while eta w decreases markedly with increasing frequency. This behaviour of eta w is called thixotropy or pseudoplasticity. 2. In the wall stress range from 5--60 kPa the values of Ed, and in the wall stress range from 60--140 kPa those of eta w obtained under smooth muscle activation and during relaxation are virtually identical. 3. In the relaxed smooth muscle, the phase angles between sinusoidal pressure and radius changes area virtually independent of the mean wall stress at all frequencies. In the low stress range, the phase angles are greater at low frequencies in the activated state than in the relaxed state, decrease with increasing wall stress, and are virtually identical to the values under papaverine at high wall stresses. At high frequencies no dependence of the phase angles on the mean wall stress can be seen.

Animals↗